how to save cartoon in mp4, i want put this on YouTube. But tis file in sifz format:disappointed_relieved:
I archived png files in tar.gz and tryed open in Kdenlive, but this doesnt work,
Did you try to render directly as a mp4?
File/Render, change the extension as .mp4
Target auto or ffmpeg (and then you can change parameters such as the codec)
The recommended process is to render as mp4 X.264 lossless and then convert it in non-linear editor such as Kdenlive 
ffmpeg -i "file.%04d.png" -b:v 10M -b:a 256k -acodec ac3 -vcodec mpeg4 -g 30 "video.mp4"
file is a name and %04d is a number. example āfile.0001.pngā
stop, i can download animation in avi
Always it is preferable to export PNG and afterwards join in the format that wish.
For example in kdenlive, bash or other software